Door-spring



V. GANDIL.

DOOR SPRING.

APPLICATION FILED JULY 10, 1918 1,337,763, Patented Apr. 20, 1920.

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ERNST VAIJDEMAR GANDIL, OF COPENHAGEN, DENMARK.

DOOR-SPRING. I

Specification of Letters Patent.

Patented Apr; 20, 1920.

Application filed July 10, 1918. Serial No. 244,219.

To aZZ whom, it may concern:

Be it known that I, ERNST VALDEMAR GANDIL, a subject of "the King'ofDenmark, residing at Copenhagen, Denmark, have invented new and usefulImprovements in Door-Springs; and I do hereby declare the following tobe a full, clear, and exact description of the same.

The invention relates to a door spring of the kind in which a springwhich is tightened during the opening of the door, closes the door whilean oil-brake efiects an even and checked closing movement. In thehitherto used door springs of this type the said spring consists in afiat spiral spring which is rather expensive and easily broken. Further,to these known constructions is attached the drawback that it isdifiicult to helical spring. VVhen' thus the former cylinder is turnedin a certain direction, the cylinders will screw themselves out of oneanother, whereby the cylinder actuated by a spring is displaced in axialdirection in such a manner that the spring is tightened and thereby putinto a position to efiect the'closing of the door.

A modification of the invention is shown in the drawing, where- Figure 1shows a section through a door spring in front view.

Fig. 2 a side view of the same and Fig. 3 a top view of the door springshown in Figs.,1 and 2 at a smaller scale and with omission of certaindetails, arranged on a door.

The casing a of the door spring, which is filled with oil, or nearly so,is integral with a plate 6, whereby it can be fixed in a verticalposition on the upper part of a door E, Fig. 3. The uppermost part ofthe casing a is bored out into a cylinder 0, in which is turnablyarranged a cylinder (1 forming a lid for the casing a. As shown in thedrawing the sliding surface between the cylinders c and d is rather longso that in this place is obtained a good closure for the oil. Inside thecylinder (Z according to the shown modification is arranged a secondcylinder 0 which is guided in perpendicular direction by a guiding listor spring f extending from the lowermost end of the cylinder e slidingina groove 9 cut in the inner side of the casing a. This groove may inan amended modification be produced as a steep helical groove in such amanner that the cylinder 6 may be allowed to carry out a slight turningmovement during the opening and closing of'the door.

A helical spring A abutting partly against the bottom of the cylinder eand partly against a normally'stationary but adjustable pistonc', tendsat pressing upward the said cylinder. A regulation of the tension of thespring can be obtained through turning of a square tap D on the end ofthe rod y' of the piston 71, the former, which is led tightly through alid Z, passing with its helical part through the bent nut-shaped end ofan arm is fastened on the lid Z.

The cylinder at rests with a collar m on the uppermost edge of thecylinder 0 and is prevented from moving upward by an arm 17 which isfixed on the casing a and forms a bearing for a tap Q on the cylinder(1, pressing a ball row 0 which is arranged in a ring-shaped groove 47.in the upward looking side of the bottom of the cylinder (Z. On the tapg is removably fastened an arm 7' which by means of a link F, turnablein both ends and with adjustable length, in a known manner is connectedwith a mounting G, fastened to the frame H above the door,

'vz'de Fig. 3.

In the side wall of the cylinder at is bored a vertical narrow channel tand in connection with the same a horizontal channel u, the free passagearea for the oil of which can be narrowed through a valve screw '21. Inthe bottom of the cylinder 6 is a conical boring 2 which through achannel w is in connection with the inner cylinder and which forms theseat for a ball as which by means of a tongue 7 not covering the entireopening 9 is in known manner prevented from leaving this opening orboring. Thus the cylinders cl and e are mutually connected and one ofthese can, by a screwing action, be moved out of and into the other.This action is, in the embodiment shown in the drawing, appropriatelyproduced by helical grooves B and A formed in the cylinders d and 6,respectively, and cut opposite to one another, said grooves jointlyforming a helical tube containing one or more balls C. As a result thereis provided a very practical construction for the'mounting anddismounting of the apparatus, and the; least" possible loss by frictionis sustained through themutual movement of the cylinders d and e.

- The cross section of the grooves A and B may be rectangular' asshownor circular.

The apparatus acts in the following manner.

When the door E is opened in the direct'ionof the arrow 1 in Fig. 3, thearm r is turned and therewith the cylinder (Z part of a revolution inthe direction indicated by the arrow 2, whereby the cylinder 6 owing' tothe screw connection A, B, C is pressed a distance downward so that thespring h is: tightened. At the same time part of the oil from thelowermost part of the casing a; is driven through the channel to and theboring a into the space above the cylinder 6, the ball as being liftedfrom its seat. When then the door is released, the strongly tightenedspring'h will lift the cylinder e and thereby turn the cylinder (Zwhereby the door is closed. As, however, the ball x will now assume itsseat, the oil cannot get this way but is forced to stream through thechannel it and the long narrow channel 2? which takes a certain time sothat the closing movement of the door is checked. 7 It will be seen thatthe special arrange ment shown in the drawing of the cylinders d and cand the'spring it. permits the casing a to be madecomparatively short,aspart of the spring h can be'accommodated in. the inner of thecylinder. 6.

' In order to suffer the oil to streamfrom one'sid e to the'other of thepiston 2' when the same'isadjusted for regulating the tension of thespring, holes 8 are bored through the said piston.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent inU. S; AI

1. A doorspringcomprising an outer casingadapted tobe secured on a doorand to contain a fluid, a hollow cylinder mounted within the said casingand adapted to be connected with a door frame and rotated uponopening'of the door, a second hollow cylinder constituting a piston andarranged to slide-tightlyin the cavity of the said first named cylinder,means, including a screw thread, for causing an axial displacement V ofthe said piston relatively to thesaid cyl inder uponturning ofthelatter, a helical spring acting upon the said piston, a valve membercarried by saidpiston and a checked channel connecting a space above thesaid pistoniwith a space below the same.

2. A doorspring comprising an outer casing adapted to be secured on adoor and to contain a fluid, a hollow cylinder-mounted within and alsoforming a lid for the said casing and adapted to be connected with adoor frame and rotated upon opening ofthe door, a'second hollow cylinderconstituting a piston and arranged to slide tightly in the cavity of thesaid first named cylinder,"

means, including a screw thread, for causing an axial displacementof thesaid'piston relatively to the said cylinder upon turning of the latter,a helical spring acting upon the said piston, a valve member carried bysaid piston and a checked channel connect ing a space abovethe saidpiston with a space below the same.

3. A doorspringcomprising an outer casing adapted-to be-secured on adoor and ,to contain a fluid, a hollow cylinder mounted withinthe: saidcasing and adapted to be connected with a doorrframe and rotated uponopening of the door, a second hollow cylinder constituting a piston andarranged to slide tightly in the cavity of the said first namedcylinder, means, including a screw thread, for causing an axialdisplacement of the said piston relatively tothe said cylinder uponturning of the latter, a helical spring partly housed in the cavity ofthe said piston and acting upon the latter, said spring abutting againstan adjustable stop arranged in the said outer casing, a valve membercarried by said piston and a checked channel connecting a space abovethe said piston with a space below the same.

4; A doorspring comprising an outer casing adaptedtobe secured on a doorand to contain a fluid, ahollow cylinder mounted within the said casingand adapted .to be connected with a door frame and rotatedchannelformediin the wall ofthe said rotatable cylinder and connecting aspace above the said piston with a space below the same. In testimonywhereof I haveaflixed my signature in presenceof two witnesses. V

ERNST VALDEMAR GANDIL. .Witnesses:

Vreeo BLoM, CECI V. Sorrow.

